Finding inputs and outputs of a two$-$step function that models a real$-$work.

$\frac{0}{3}$

A construction crew needs to pave a road that is $209$ miles long. The crew paves $7$ miles of the road each day. The length, $L($in miles$),$ that is left to be paved after $d$ days is given by the following function.

$L(d)=209-7d$

Answer the following questions.

$($a$)$ If $146$ miles of the road is left to be paved, how many days has the crew been paving the road?

$9$ days

$($b$)$ How many miles of the road does the crew have left to pave after $11$ days?

miles